If I wanted to say 'I like to go for walks' where does 'gern' go?
My guess is
Ich gehe gern spazieren.
Is this correct?
If I wanted to say 'I like to go for walks' where does 'gern' go?
My guess is
Ich gehe gern spazieren.
Is this correct?
Yes. Adverbs precede the verb phrase they modify, just as in English. Let me show you a slightly different example:
Du weißt, dass ich abends gern spazieren gehe.
In main clauses, the V2 rule requires you to move the stem of the conjugated verb to second position however:
Ich gehe abends gern spazieren.
See how this works? The conjugated verb is moved, everything else stays where it was.
Note, that there is no separable verb »spazierengehen« since the orthographic reform of 1996. This separable verb used to exist before that year, but since 1996 it must be replaced by the two words »spazieren« and »gehen«.
Ich möchte spazierengehen.
Ich möchte spazieren gehen.
So, the modern usage is similar to »einkaufen gehen« which also is a combination of two verbs:
Ich möchte einkaufen gehen.
There never was a verb »einkaufengehen«, so »einkaufen gehen« was also the correct usage before 1996.
But you don't see any differences in situations where separable verbs must be separated:
Ich gehe spazieren.
Ich gehe einkaufen.
This usage together with the infinite form of another verb is a special feature of the verb gehen. So, this works without the need to glue the two verbs together to one separable verb.
The rules for word oder are the always the same:
From all other parts of speech, exactly one must stand at position 1, and anything else must be placed between the inflected verb at position 2 and all other verb-like words which must stand at the very end of the main clause. This is called »Satzklammer« or »Verbklammer« in German. English doesn't have this feature, so there is no established English term for it, but I would call it »verbal bracket«. Only if you want to emphasize a part of speech extremely strongly, it can be placed behind the last verb (or former prefix of a separable verb), but there are limitations.
These are allowed word orders for your sentence:
Ich gehe gern spazieren.
Gern gehe ich spazieren.
Word order 1 is the normal and preferred form. Word order 2 is another allowed form, it emphasizes the word »gern«.
Note, that in the example »ich möchte spazieren gehen« which I gave before, the word »möchte« does not squeeze between »spazieren« and »gehen« because »möchte« by itself is a verb, (a modal verb) and it is even the inflected verb, so it is the opening part of the verbal bracket. All other verbs (here: »spazieren« and »gehen«) belong to the closing part of the verbal bracket and must stand at the end of the sentence:
2 verbs: gehen + infinite verb
Ich gehe spazieren.
Ich gehe am Muttertag mit meiner Mutter, die ich schon seit Monaten nicht mehr gesehen habe, endlich wieder mal spazieren.
3 verbs: modal verb + (infinite verb + gehen)
Ich möchte spazieren gehen.
Ich möchte am Muttertag mit meiner Mutter, die ich schon seit Monaten nicht mehr gesehen habe, endlich wieder mal spazieren gehen.
4 verbs: auxiliary verb + [(infinite verb + gehen) + modal verb]
Ich werde spazieren gehen wollen.
Ich werde am Muttertag mit meiner Mutter, die ich schon seit Monaten nicht mehr gesehen habe, endlich wieder mal spazieren gehen wollen.